Hi,
Thank you. I get your point.
Actually I just would like to collect more information and experience from other developers before I bring the possible solutions to my boss and my client. It is not a easy work because nobody in my company experienced in such case, no other suggestions will be come out from others either beside me, and also do something to my client because they are running business and cannot be stop even just a minute. Even though myself can work OT and work at midnite for this, that may not have any coorperation from client site.

Anyway, thank you very much on yours sugesstion. I am really appreaciate for that. Thank you very much